Air-curtain forming apparatus for wafer hermetic container in semiconductor-fabrication equipment of minienvironment system

ABSTRACT

In a semiconductor-fabrication equipment of a minienvironment system, ambient air is prevented from entering a gap between an opening of the semiconductor-fabrication equipment and a wafer gateway of a hermetic container to prevent dust entrained in the ambient air from adhering to wafers in the hermetic container. Clean air is injected from a clean-air injection device ( 1 ), which is connected to an air-supply device ( 2 ) through an air-supply tube ( 3 ), and which is provided with filter means ( 6   a ) in the from of rectangular frame formed with cylindrically-shaped filters connected to each other, to form an air curtain at the gap ( 96 ) between the gateway ( 74 ) of the hermetic container ( 71 ) through which wafers ( 73 ) are taken out of or put in the hermetic container ( 71 ) and the opening ( 98 ) of a loading part ( 78 ) attached to a front panel ( 77 ) of the semiconductor-fabrication equipment ( 76 ), thereby shutting off the ambient air that would otherwise enter the hermetic container ( 71 ) through the gap ( 96 ) between the gateway ( 74 ) of the hermetic container ( 71 ) and the opening ( 98 ) of the loading part ( 78 ) attached to the semiconductor-fabrication equipment ( 76 ) when a lid ( 75 ) of the hermetic container ( 71 ) is opened into the semiconductor-fabrication equipment ( 76 ).

FIELD OF THE INVENTION

This invention relates to a semiconductor-fabrication equipment of aminienvironment system used in a clean room for producingsemiconductors.

DESCRIPTION OF THE PRIOR ART

Conventionally, in a clean room for producing semiconductors, aminienvironment system is adapted, where wafers are transferred andhandled in a hermetic container to reduce investment and save energy.Recently, to obtain many semiconductor chips from a single wafer, awafer of the size of 300 mm in diameter has become to be used.

In the minienvironment system of the 300 mm diameter wafer generation, aspecification for a hermetic container to accommodate wafers and aspecification for a loading part that transfers the wafers from thehermetic container into a semiconductor-fabrication equipment and fromit into the hermetic container are international standards.

A conventional semiconductor-fabrication equipment of theminienvironment system, which is installed in a clean room 70, isconfigured as shown in FIG. 36 through 38. FIG. 36 is a schematiccross-sectional view of the conventional semiconductor-fabricationequipment of the minienvironment system 76, and FIG. 37 is an explodedperspective view of a hermetic container 71 and a loading device 78.FIG. 38 is a cross-sectional view of the main portion of theconventional semiconductor-fabrication equipment, where the hermeticcontainer 71 accommodates wafers 73, which are vertically arranged init, at its accommodating portion 72. The hermetic container 71 can beclosed by closing a gateway 74 for the wafers 73 by a lid 75 and isplaced on a movable table 79, which can be moved to and away from aloading part 78 securely attached to a front panel 77 of thesemiconductor-fabrication equipment 76.

The semiconductor-fabrication equipment 76 is divided into two spaces bya separating wall 80 located at the center of the device 76, namely, afront, high cleanliness space 81 and a rear, low cleanliness space 82.

A fan filter unit 85, comprising a fan 83 and a filter 84, is installedat a ceiling of the high cleanliness space 81, and clean air 86 issupplied from the fan filter unit 85 to the high cleanliness space 81,keeping there a high cleanliness atmosphere.

An opening 87 is formed in the front panel 77 of the high cleanlinessspace 81 (which panel 77 constitutes the semiconductor-fabricationequipment 76) at a position that faces the lid 75 of the hermeticcontainer 71, so that the opening 87 is connected to an opening 98 ofthe loading part 78 to act as a passage for the wafers 73 when they aredrawn out from the hermetic container 71 into the high cleanliness space81 or when they are placed in the hermetic container 71.

An electric motor 88 is fixedly mounted on the inner, lower surface ofthe front panel 77 and is connected to an opening/closing arm 89 througha speed reducer (not shown) to move the arm 89 vertically and forwardlyand backwardly. A plate 90 is fixedly mounted on the opening/closing arm89 at its upper end located at the opening 87 so as to engage with andthen open or close the lid 75. The number 91 denotes engagingprojections formed on the plate 90, for engaging with correspondingreceiving portions 92 formed on the lid 75 so as to secure the plate 90to the lid 75.

Further, a robot 94 is also installed in the high cleanliness space 81.The robot is provided with an arm 93 at its upper part for drawing awafer 73 from the hermetic container 71 into the high cleanliness space81 or inserting the wafer into the hermetic container 71. A wafer 73 isdrawn into the high cleanliness space 81 by the arm 93 and is thentransferred by the robot 95 to a chamber 95 located in the lowcleanliness space 82 and is the processed in the chamber 95. Theprocessed wafer 73 is moved onto the arm 93 and then placed in thehermetic container 71.

In operation, to draw a wafer 73 from the hermetic container 71 onto thearm 93, the electric motor 88 is operated first to forward theopening/closing arm 89 to engage the engaging projections 91 of theplate 90 with the receiving portions 92 of the lid 75 of the hermeticcontainer 71, so that the plate 90 and the lid 75 are secured together.The opening/closing arm 89 is then moved back to draw the lid 75together with the plate 90 into the high cleanliness space 81, to openthe container 71. The opening/closing arm 89 is then lowered to open theopenings 87 and 98, and the operation of the electric motor 88 is thenstopped.

The robot 94 is then operated to move the arm 93 through the openings 87and 98 until the arm 93 is located under a wafer 73, which is now to betransferred. The wafer 73 is carried on the arm 93 and drawn by it fromthe hermetic container 71 into the high cleanliness space 81 of thesemiconductor-fabrication equipment 76 and is further moved into thechamber 95 of the low cleanliness space 81 of thesemiconductor-fabrication equipment 76 by the robot 94 for beingprocessed in the chamber 95.

The wafer 73, which has been drawn into the high cleanliness space 81and into the chamber 95 and processed therein, is placed on the arm 93by operating the robot 94 and passed through the openings 87, 98 and theopened gateway 74 into the hermetic container 71. By repeating theoperation, all the wafers 73 are in turn carried into thesemiconductor-fabrication equipment 76 and processed there. When theprocess has been completed for all the wafers 73 in the hermeticcontainer 71, the electric motor 88 is operated to raise and thenforward the opening/closing arm 89 to attach the lid 75, which issecured to the plate 90 of the opening/closing arm 89, to the gateway 74of the hermetic container 71. By disengaging the engaging projections 91from the receiving portions 92, the hermetic container 71 is closed.

In the hermetic container 71 and the loading part 78 specified by theconventional standards, as shown in FIG. 38 the fundamental designthought is an idea to prevent the streams of the ambient air 97, 97(shown by solid arrows), which may enter the hermetic container 71 froma gap 96 between the gateway 74 of the hermetic container 71 and theopening 98 of the loading part 78 when the lid 75 of the hermeticcontainer 71 located at the loading part 78 is opened and moved into thehigh cleanliness space 81 of the semiconductor-fabrication equipment 7by the opening/closing arm 89, from entering the hermetic container 71by the streams of air 99, 99 (shown by dotted-line arrows) injected froma gap 96, which air is supplied by the fan filter unit 85. Further,since a plurality of openings 101 are formed in the floor 100 of thesemiconductor device 76 to cause the cleanliness air to flow downward inlayers, the fan filter unit 85 must increase the pressure in the highcleanliness space 81 to cause the streams 99, 99 to be sufficientlystrongly injected, to prevent the streams of ambient air 97, 97 fromentering the hermetic container 71. To that end, the amount and pressureof the air from the fan filter unit 85 must be made great. However, ifthe amount and pressure of the air from the fan filter unit 85 are madegreat, the cleanliness air 86 cannot be formed as layers, and thus thedesirable cleanliness cannot be kept in the high cleanliness space 81.Accordingly, in the hermetic container 71 and the loading part 78specified by the conventional standards, a sufficient amount andpressure of the air cannot be insured from the fan filer unit 85. Thusthe streams of the ambient air 97, 97 shown in the solid arrows enterthe hermetic container 71 through the gap 96, thereby causing a problemin that the dust entrained in the entered air adheres to the wafers inthe hermetic containers 21.

The present invention has been conceived to resolve that problem, and itaims to provide a semiconductor-fabrication equipment of aminienvironment system wherein an air curtain is formed around theperiphery of an opening of the loading part attached to the front panelof the semiconductor-fabrication equipment, which opening acts as thepassage for the wafer, by attaching or embedding a clean-air injectiondevice to the periphery of the opening, for injecting clean air at thegap between the opening and the wafer gateway of the hermetic container,preventing dust-entraining ambient air from passing through the gap sothat the dust does not adhere to the wafers in the hermetic container.

SUMMARY OF THE INVENTION

The problem discussed above is resolved by adapting one of the followingmeans:

In a semiconductor-fabrication equipment of a minienviroment systemwherein a wafer in a hermetic container is taken out into thesemiconductor-fabrication equipment, and a processed wafer is put in thehermetic container, an clean-air injection device, which is connected toan air-supply device through an air-supply tube, is attached to theperiphery of an opening of the semiconductor-fabrication equipment, theclean-air injection device includes a filter means of cylindricallyshaped filters connected to each other to be a rectangular frame; afilter case formed as a rectangular frame for encasing the filter means;and a guide cover formed with an injection slit and a guide slit infront of the filter case, wherein an clean air is injected from theclean-air injection device to form an air curtain at a gap between anopening of a loading part attached to the semiconductor-fabricationequipment and a gateway of the hermetic container through which a waferis taken out of or put in the hermetic container so as to prevent anambient air from passing through the gap into the hermetic containerwhen a lid of the hermetic container is opened to thesemiconductor-fabrication equipment;

In a semiconductor-fabrication equipment of a minienviroment systemwherein a wafer in a hermetic container is taken out into thesemiconductor-fabrication equipment, and a processed wafer is put in thehermetic container, an clean-air injection device, which is connected toan air-supply device through an air-supply tube, is embedded in theperiphery of an opening of the semiconductor-fabrication equipment, theclean-air injection device includes a filter means of cylindricallyshaped filters connected to each other to be a rectangular frame, thefilter means being encased in a rectangular notch formed at theperiphery of the opening; and a cover formed with an injection slit anda guide slit and secured to the notch, wherein an clean air is injectedfrom the clean-air injection device to form an air curtain at a gapbetween an opening of a loading part attached to thesemiconductor-fabrication equipment and a gateway of the hermeticcontainer through which a wafer is taken out of or put in the hermeticcontainer so as to prevent an ambient air from passing through the gapinto the hermetic container when a lid of the hermetic container isopened to the semiconductor-fabrication equipment;

In a semiconductor-fabrication equipment of a minienviroment systemwherein a wafer in a hermetic container is taken out into thesemiconductor-fabrication equipment, and a processed wafer is put in thehermetic container, an clean-air injection device, which is connected toan air-supply device through an air-supply passage disposed in a frontpanel of the semiconductor-fabrication equipment, is embedded in theperiphery of an opening of the semiconductor-fabrication equipment, theclean-air injection device includes a filter means of cylindricallyshaped filters connected to each other to be a rectangular frame, thefilter means being encased in a rectangular notch formed at theperiphery of the opening; and a cover formed with an injection slit anda guide slit and secured to the notch, wherein an clean air is injectedfrom the clean-air injection device to form an air curtain at a gapbetween an opening of a loading part attached to thesemiconductor-fabrication equipment and a gateway of the hermeticcontainer through which a wafer is taken out of or put in the hermeticcontainer so as to prevent an ambient air from passing through the gapinto the hermetic container when a lid of the hermetic container isopened to the semiconductor-fabrication equipment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic sectional view of a first embodiment of thesemiconductor-fabrication equipment of a minienvironment system of thepresent invention, wherein the semiconductor-fabrication equipment has aclean-air injection device to be attached to the periphery of theopening of a loading part.

FIG. 2 is a schematic sectional view of the first embodiment of FIG. 1,showing the main part of the semiconductor-fabrication equipment.

FIG. 3 is a partly sectional front view of the clean-air injectiondevice of the first embodiment, wherein a part of a filer means of theclean-air injection device is cut away.

FIG. 4 is a schematic perspective view showing the clean-air injectiondevice of the first embodiment and an air-supply device.

FIG. 5 is a perspective view of the clean-air injection device of thefirst embodiment, wherein a part of it is cut away.

FIG. 6 is a front view of the clean-air injection device of the firstembodiment, wherein a part of it is cut away.

FIG. 7 is a cross-sectional view of the clean-air injection device ofthe first embodiment.

FIG. 8 is an exploded view of the clean-air injection device of thefirst embodiment.

FIG. 9 is a partly sectional front view of the clean-air injectiondevice of a second embodiment of the semiconductor-fabrication equipmentof the present invention, adapted to be attached to the periphery of theopening of the loading part.

FIG. 10 is a schematic perspective view of the clean-air injectiondevice of the second embodiment and an air-supply device.

FIG. 11 is a partly sectional front view of a clean-air injection deviceof a third embodiment of the semiconductor-fabrication equipment of aminienvironment system of the present invention, adapted to be attachedto the periphery of the opening of the loading part, wherein a part offilter means of the clean-air injection device is cut away.

FIG. 12 is a schematic perspective view of the clean-air injectiondevice of the third embodiment and an air-supply device.

FIG. 13 is a partly sectional perspective view of a clean-air injectiondevice of a fourth embodiment of the semiconductor-fabrication equipmentof a minienvironment system of the present invention, adapted to beattached to the periphery of the opening of the loading part, wherein apart of filter means of the clean-air injection device is cut away.

FIG. 14 is a cross-sectional view of the clean-air injection device ofthe fourth embodiment.

FIG. 15 is an exploded view of the clean-air injection device of thefourth embodiment.

FIG. 16 is a schematic perspective view of the clean-air injectiondevice of the fourth embodiment and an air-supply device.

FIG. 17 is a partly sectional perspective view of a clean-air injectiondevice of a fifth embodiment of the semiconductor-fabrication equipmentof a minienvironment system of the present invention, adapted to beattached to the periphery of the opening of the loading part, wherein apart of filter means of the clean-air injection device is cut away.

FIG. 18 is a partly sectional view of the clean-air injection device ofthe fifth embodiment and an air-supply device, wherein a part of theclean-air injection device is cut away.

FIG. 19 is a partly sectional perspective view of a clean-air injectiondevice of a sixth embodiment of the semiconductor-fabrication equipmentof a minienvironment system of the present invention, adapted to beattached to the periphery of the opening of the loading part, wherein apart of filter means of the clean-air injection device is cut away.

FIG. 20 is a partly sectional, schematic perspective view of theclean-air injection device of the sixth embodiment and an air-supplydevice, wherein a part of the clean-air injection device is cut away.

FIG. 21 is a partly sectional perspective view of a clean-air injectiondevice of a seventh embodiment of the semiconductor-fabricationequipment of a minienvironment system of the present invention, adaptedto be attached to the periphery of the opening of the loading part,wherein a part of filter means of the clean-air injection device is cutaway.

FIG. 22 is a cross-sectional view of the clean-air injection device ofthe seventh embodiment.

FIG. 23 is an exploded view of the clean-air injection device of theseventh embodiment.

FIG. 24 is a partly sectional, schematic perspective view of theclean-air injection device of the seventh embodiment and an air-supplydevice, wherein a part of the clean-air injection device is cut away.

FIG. 25 is a partly sectional perspective view of a clean-air injectiondevice of a eighth embodiment of the semiconductor-fabrication equipmentof a minienvironment system of the present invention, adapted to beattached to the periphery of the opening of the loading part, wherein apart of filter means of the clean-air injection device is cut away.

FIG. 26 is a partly sectional, schematic perspective view of theclean-air injection device of the eighth embodiment and an air-supplydevice, wherein a part of the clean-air injection device is cut away.

FIG. 27 is a partly sectional perspective view of a clean-air injectiondevice of a ninth embodiment of the semiconductor-fabrication equipmentof a minienvironment system of the present invention, adapted to beattached to the periphery of the opening of the loading part, wherein apart of filter means of the clean-air injection device is cut away.

FIG. 28 is a partly sectional, schematic perspective view of theclean-air injection device of the ninth embodiment and an air-supplydevice, wherein a part of the clean-air injection device is cut away.

FIG. 29 is a schematic sectional view of the main part of thesemiconductor-fabrication equipment of a minienvironment system of theinvention provided with the clean-air injection device of the firstembodiment.

FIG. 30 is a schematic front view of the main part of FIG. 29, takenfrom the loading side.

FIG. 31 is a schematic sectional view of the main part of thesemiconductor-fabrication equipment of a minienvironment system of theinvention provided with the clean-air injection device of the secondembodiment.

FIG. 32 is a schematic front view of the main part of FIG. 31, takenfrom the loading side.

FIG. 33 is a schematic sectional view of the main part of thesemiconductor-fabrication equipment of a minienvironment system of theinvention provided with the clean-air injection device of the thirdembodiment.

FIG. 34 is a schematic front view of the main part of FIG. 33, takenfrom the loading side.

FIG. 35 is a cross-sectional view of an air-supply passage of thesemiconductor-fabrication equipment of a minienvironment system providedwith the clean-air injection device of the third embodiment.

FIG. 36 is a schematic sectional view of a conventionalsemiconductor-fabrication equipment of a minienvironment system.

FIG. 37 is an exploded view of a hermetic container and a loading deviceof the conventional semiconductor-fabrication equipment of aminienvironment system.

FIG. 38 is a schematic sectional view of the main part of theconventional semiconductor-fabrication equipment of a minienvironmentsystem.

In the drawings, the number 1 denotes a clean-air injection device; 2 anair-supply device; 3 an air-supply tube; 6 a-6 i filter means; 7 afilter box; 8 a guide lid; 10 a cylindrically-shaped filter; 71 ahermetic container; 73 a wafer; 74 a gateway; 76 asemiconductor-fabrication equipment; 77 a front panel; 78 a loadingpart; 96 a gap; 98 an opening; 111 a clean-air injection device; 112 anair-supply device; 113 an air-supply tube; 114 a notch; 115 acylindrically-shaped filter; 119 filter means; 121 injecting slit; 122 aguide plate; 123 a cover; and 131 an air-passage line.

PREFERRED EMBODIMENTS OF THE INVENTION

The embodiments of the present invention are now explained withreference to the accompanying drawings, wherein the same referencenumbers are used for the same elements that are also used in theconventional semiconductor device discussed above, and explanations forthe structure and the function of those elements are omitted.

In the semiconductor-fabrication equipment of a minienvironment systemof the present invention, a clean-air supply device 1 is attached to orembedded in the periphery of an opening 98 of a loading part 78 of aconventional semiconductor-fabrication equipment 76. The opening 98 ofthe loading part 78 is formed in a front panel 77 of the conventionalsemiconductor-fabrication equipment 76 to act as a passage for drawing awafer 73 in a hermetic container 71 from it into a high cleanlinessspace 81 of the semiconductor-fabrication equipment 76 and for placingthe wafer 73 from the semiconductor-fabrication equipment 76 into thehermetic container 71. Clean air is injected from the clean-airinjection device 1, which is connected to an air-supply device,outwardly at the outer periphery of the opening 98 to form an aircurtain between the gateway 74 of the hermetic container 71 and theopening 98, preventing the dust-entraining ambient air in the clean roomfrom entering the hermetic containers 71, i.e., preventing the dust fromadhering to the wafers 73.

FIG. 1 is a schematic sectional view of a semiconductor-fabricationequipment of a minienvironment system of the present invention providedwith a first embodiment of a clean-air injection device 1 a, which isattached to the periphery of the opening 98 of the loading part 78. Theloading part 78 of the semiconductor-fabrication equipment installed ina clean room 70 shown in FIG. 1 is a one specified by a world standardspecification. A clean-air injection device 1 a and an air-supply device2 are disposed in a limited space of a high cleanliness space 81 of thesemiconductor-fabrication equipment, which space 81 is specified by aworld standard specification.

In the semiconductor-fabrication equipment of a minienvironment systemof the present invention provided with the clean-air injection device ofthe type to be attached to the periphery of the opening 98 of theloading part 78, the clean-air injecting device 1 a of the firstembodiment is connected to the air-supply device 2 through an air-supplytube 3 such that the clean-air injecting device 1 a and air-supplydevice 2 are separately disposed in the limited space in thesemiconductor-fabrication equipment 76.

The clean-air injecting device 1 a is shaped as a thin rectangular frameand is fixedly mounted on the periphery of the opening 98 of the loadingpart 78 so that it does not hinder the plate 90 from moving verticallyand forwardly and backwardly. Further, the air-supply device 2 is alsoshaped as a thin body so that it does not hinder the electric motor 88and the opening/closing arm 89 from moving and is mounded on the innersurface of the front panel 77, being spaced apart from the electricmotor. Since the air-supply device 2 must be thin, it has an annularair-suction part 5 provided with a sirocco fan 4 for air suction asshown in FIG. 4. The sirocco fan 4 sucks clean air in the highcleanliness space 81 and supplies it to the clean-air injection device 1a through the air-supply tube 3.

As shown in FIGS. 1 and 2, the clean-air injection device 1 a, which isfixedly mounted on the periphery of the opening 98 of the loading part78 attached to the front panel 77 of the of thesemiconductor-fabrication equipment 76, is configured to injectclean-air outwardly at the outer edge of the periphery of the opening98. In the first embodiment of this invention, clean-air injectingdevice 1 a is formed as a rectangular frame to meet the rectangularopening 98.

Specifically, the clean-air injecting device 1 a is composed by filtermeans 6 a, a filter case 7 for encasing the filter means 6 a, and arectangular guide cover 8 disposed at the front surface, i.e., thedownstream side, of the filter case 7

The filter means 6 a define a rectangular or annular air passage 9.Cylindrical filters 10, which are shaped by rounding filter material,and which are connected to each other at their ends by L-joints 11, formthe air passage 9. The filter means 6 a defines a space in its innerside, which space is slightly larger than the periphery of the opening98. One of the lateral filters 10 (the upper lateral filter in FIG. 3)is cut at its central part, proving a spacing part 13 between the cutend surfaces 10 a and 10 b, and the end surfaces 10 a and 10 b areconnected by a I-shape joint 14. The I-joint 14 has an air-feed tube 15extending upwardly and having an air-feed port 15 a at the top connectedto the air-supply device 2.

The filter case 7 is formed as a rectangular frame by connectingchannel-shaped plates 20, each of which is formed by jointing sideplates 16 and a back plate 17. The channel-shaped plate 20 has a cavity18 having a width that is greater than the diameter of the cylindricalfilter 10, and it has also opening 19 at its front, i.e., the downstreamside. The filter case 7 defines a space 21 at its center, which isslightly greater than the periphery of the opening 98. Further, anaperture 22 is formed in the upper outer side plate 16 as shown in FIG.6 so that the air-supply tube 15 can pass through it. In the drawing thenumber 23 denotes a seal applied to the joint of the aperture 22 and theair-supply tube.

Further, the guide cover 8 is removably mounted on the filter case 77 atits front opening 19. The guide cover 8 includes sliding pieces 24 andguide plates 26 perpendicularly secured to the sliding pieces 24. Thesliding pieces 24 can be slidably fitted on the inner surfaces of theside plates 16, 16. The guide plates 26 forms a slit therebetweenextending along the length of the guide cover, for injecting clean airinjected from the filter means 6 a. Further, inclined rectifier plates28, 28 are fixed to the guide plates 26, 26, forming a guide slit 29therebetween for guiding the clean air injected from the slit 25 and forunifying the distribution of the clean air. The rectifier plates arejointed at some points therebetween by spot welding 28 a. The slidingpieces 24, guide plates 26, rectifier plates of the cover 8 are formedas rectangular frames, respectively, and the cover 8 defines a space 27at its center, the size of which is the same as that of the filter case.

Although it is not necessary to limit the sizes of the injection slit 25and the guide slit 29 to any special one, they are preferably a 1.5 mmin width. Further, the points of the spot welding 28 a are preferablyspaced about 5 cm.

The sliding pieces 24 of the guide cover 8 configured as discussed aboveare inserted into the openings 19 at the front of the filter case 7 andare slidably moved along and engaged with the inner surfaces of the sideplates 16, so that the guide cover 8 is detachably secured to the filtercase 7, to form the clean-air injection device 1 a.

The clean-air injection device 1 a is attached to the periphery of theopening 98 so that the guide slit 29 faces to the gap 96 between theopening 98 and the gateway 74 of the hermetic container 71. Further, theair-supply port 30 of the air-supply device 2 is connected to theair-feed port 15 a of the clean-air injection device 1 a via theair-supply tube 3.

The air in the high cleanliness space 81 is pumped by the clean-airsupply device 2 into the filter means 6 a through the air-feed port 15a, i.e., into the air passage 9 of each cylindrical filter 10 of thefilter means 6 a, and is then filtered by the filter material of thefilter 10 and is injected into the cavity 18 of the filter case 7 asmore clean air than the clean air in the high cleanliness space 81. Themore clean air is then injected from the injection slit 25 and is thenrectified by the rectifier plates 28 and ejected from the guide slit 29as a stream having a uniformed pressure distribution.

Since the filter means 6 a of the clean-air injection device 1 a isformed by using the cylindrically shaped filters 10, the flow resistanceof the cylindrically shaped filters 10 in the passage is less than thefilter loss (about 200 Pa). Thus the injection speed of the clean airfrom the injection slit 25 is substantially uniformly kept at any partof the slits, which is near or remote from the air-feed port 15 a. Thatis, the air injection speed at the injection slit 25 of the uppercylindricaly-shaped filter 10, which is located at the air-feed tube 15side, is substantially the same as the air injection speed at theinjection slit 25 of the lower cylindricaly-shaped filter 10, which islocated opposite to the upper cylindricaly-shaped filter 10.

Since all the air injected from the cylindrically shaped filters 10 isclean air, applying sealing to the filter case 7 or the guide cover 8 isnot necessary, except for the part to which the sealing 23 is applied.

Further, since the guide cover 8 is fitted between the side plates 16 ofthe filter case 7 with the sliding pieces 24 of the guide cover 8slidably engaging the inner surfaces of the side plates 16, it can beeasily separated from the filter case 7, and the used filter means 6 acan be changed with a new one.

FIG. 9 is a front view of filter means 6 b of a clean-air injectingdevice 1 b of the second embodiment of the type to be attached to theperiphery of the opening 98 of the loading part 78 of thesemiconductor-manufacturing equipment of the minienvironment system ofthe present invention. The filter means 6 b is formed as a rectangularframe with cylindrically shaped filters 10, which are formed as in thefilter means 6 a and connected by L-joints 11. The filter means 6 bdefine a rectangular air passage 9 and have a space 12 in its innerside, which is slightly greater than the periphery of the opening 98.Two of the L-joints 11 located one side of the filter means 6 b, i.e.,the left or right side, (in FIG. 9, the left side) have air-feed pipes15 laterally projecting and having air-feed ports 15 a.

The filter means 6 b configured as discussed above is encased in therectangular cavity 18 of a filter case 7, which is similar to the filtercase 7 of the first embodiment, wherein apertures 22, 22 are formed inthe outer side plate 16 so that the laterally extending air-feed pipes15 pass through them. The guide cover 8 the same as in the firstembodiment is detachably secured to the filter case 7 at its front, toform a clean-air injection device 1 b.

Since the clean-air injection device 1 b of the second embodiment hastwo air-feed ports 15 a for receiving air supply from the air-supplydevice 2, the air-supply tube 3 is divided to two sub-air-supply tubes 3a, 3 b through a dividing box 31, as shown in FIG. 10. In the drawing,the number 23 denotes sealing applied to the junctions of the air-feedpipes 15 and the apertures 22 of the filter case.

Using the clean-air injection device 1 b of the second embodiment causesthe injection speed of the clean air to be injected more uniformly andcauses the flow rate of the air injected to be greater than using theclean-air injection device 1 a of the first embodiment. Since the otherfunctions of it are the same as in the first embodiment, the descriptionfor them is omitted.

FIG. 11 is a front view of filter means 6 c of a clean-air injectingdevice 1 c of the third embodiment of the type to be attached to theperiphery of the opening 98 of the loading part 78 of thesemiconductor-manufacturing equipment of the minienvironment system ofthe present invention. The filter means 6 c is formed as a rectangularframe with cylindrically shaped filters 10, which are formed as in thefilter means 6 a and connected by L-joints 11. The filter means 6 cdefine a rectangular air passage 9 and have a space 12 in its innerside, which is slightly greater than the periphery of the opening 98.Each of four L-joints 11 has an air-feed pipe 15 laterally projectingand having air-feed ports 15 a.

The filter means 6 c configured as discussed above is encased in therectangular cavity 18 of a filter case 7, which is similar to the filtercase 7 of the first embodiment, wherein apertures 22 are formed in theouter side plates 16 so that the laterally extending air-feed pipes 15pass through them. The guide cover 8 the same as in the first embodimentis detachably secured to the filter case 7 at its front, to form aclean-air injection device 1 c.

Since differing from the first embodiment, the clean-air injectiondevice 1 c of the third embodiment has two air-feed ports 15 a forreceiving air supply from the air-supply device 2, the air-supply tube 3is divided to four sub-air-supply tubes 3 a, 3 b, 3 c, and 3 d through adividing box 31, as shown in FIG. 12. In the drawing, the number 23denotes sealing applied to the junctions of the air-feed pipes 15 andthe apertures 22 of the filter case.

Using the clean-air injection device 1 c of the third embodiment causesthe injection speed of the clean air to be injected more uniformly andcauses the flow rate of the air injected to be greater than using theclean-air injection device 1 a of the first embodiment. Since the otherfunctions of it are the same as in the first embodiment, the descriptionfor them is omitted.

FIG. 13 is a perspective view of filter means 6 d of a clean-airinjecting device 1 d of the fourth embodiment of the type to be attachedto the periphery of the opening 98 of the loading part 78 of thesemiconductor-manufacturing equipment of the minienvironment system ofthe present invention. The same as in the first embodiment, theclean-air injecting device 1 d, which is provided with the filter means6 d, is connected to the air-supply device 2 through an air-supply tube3 as shown in FIG. 16. However, the fourth embodiment of the clean-airinjection device 1 d differ from the first embodiment of the clean-airinjection device 1 a in that in the filter means 6 a of the firstembodiment the cylindrical filters 10 are formed as a single row of arectangular frame, while in the filter means 6 d of the fourthembodiment the cylindrical filters 10 are formed as a plurality of rowsof rectangular frames (two rows in FIG. 16).

The clean-air injection device 1 d of the fourth embodiment may be usedwhen the air to be injected is increased by increasing the area of thefilters, or when the depth of the cylindrically shaped filters 10 can begreat, but other sizes must be small. In this embodiment the area of thefilters can be increased to increase the air to be injected.

In the filter means 6 d the cylindrically shaped filters 10 are disposedin two rows in the direction of depth and are jointed at their ends byL-joints 32, which have an enough depth, to define rectangular doublepassages 9 for air and an inside space 12, which is larger than theperiphery of the opening 98. Further, the central parts of the upper orlower rows of the cylindrically shaped filters 10 (the upper rows inFIG. 13) are cut away to form a spacing part 13 between cut ends 10 aand 10 b, and the cut ends are connected by a I-joint 33, which has aenough size in the direction of depth, and which has an air-feed pipe 15extending upwardly and having an air-feed port 15 a for receiving airfrom the air-supply device 2.

The filter means 6 d configured as discussed above is disposed in therectangular cavity 18 of a filter case 7. The cavity 18 has a greatdepth so that the double rows of the cylindrically shaped filters 10 areencased in it as shown in FIGS. 14 and 15. An aperture 22 is formed inthe outer side plate 16 of the case 7 so that the outwardly extendingair-feed tube 15 of the I-joint 33 passes through it. Further, the guidecover 8 configured as in the first embodiment is detachably secured tothe filter case 7 at its opening 19, to form the clean-air injectiondevice 1 d as shown in FIG. 16. In FIG. 16 the number 23 denotes sealingapplied to the junction of the air-feed tube 15 and the aperture 22 ofthe filter case 7.

One function of the fourth embodiment that differs from the firstembodiment is that it can increase the air to be injected by increasingthe area of the filters. The other functions of it are the same in thefirst embodiment, and thus the description for them is omitted.

FIG. 17 is a perspective view of filter means 6 e of a clean-airinjecting device 1 e of the fifth embodiment of the type to be attachedto the periphery of the opening 98 of the loading part 78 of thesemiconductor-manufacturing equipment of the minienvironment system ofthe present invention. Like the filter means 6 d of the clean-airinjecting device 1 d of the fourth embodiment, the filter means 6 e isformed as a rectangular frame by cylindrically shaped filters 10disposed in a plurality rows (two rows in FIG. 17) and connected to eachother at their ends by L-joints 32, which have an enough depth, todefine rectangular double passages 9 for air and an inside space 12,which is slightly larger than the periphery of the opening 98. Further,two of the L-joints 32, located at the left or right side of the filtermeans 6 e (the left side in FIG. 17) have air-feed pipes 15 extendinglaterally and having air-feed ports 15 a for receiving air from theair-supply device 2.

The filter means 6 e configured as discussed above is disposed in therectangular cavity 18 of a filter case 7. The cavity 18 has a depthgreater than that of the cavity 18 of the filter case 7 of the firstembodiment and is configured the same as the cavity 18 of the filtercase 7 in FIGS. 14 and 15, so that the double rows of the cylindricallyshaped filters 10 are encased in it. Apertures 22 are formed in theouter side plate 16 of the case 7 so that the outwardly extendingair-feed tubes 15 of the two L-joints 32 pass through them. Further, theguide cover 8 configured as in the first embodiment is detachablysecured to the filter case 7 at its opening 19, to form the clean-airinjection device 1 e as shown in FIG. 18. In FIG. 18 the number 23denotes sealing applied to the junctions of the air-feed tubes 15 andthe apertures 22 of the filter case 7.

Differing from the clean-air injection device 1 d of the fourthembodiment, the clean-air injection device 1 e of the fifth embodimenthas the two air-feed ports 15 a to receive air from the air-supplydevice 2. Accordingly, the air supply tube 3, which is connected to theair-supply device 2 at one end, is branched to two sub-air-supply tubes3 a, 3 b, which are in turn connected to the air-feed tubes 15. Usingthe clean-air injection device 1 e of the fifth embodiment can cause theair to be more uniformly injected from the injection slit 25 and cangive a greater flow rate of the air injected from it than using theclean-air injection device 1 d of the fourth embodiment. The otherfunctions of it are the same as the clean-air injection device 1 a ofthe first embodiment, and thus the description for them is omitted.

FIG. 19 is a perspective view of filter means 6 f of a clean-airinjecting device 1 f of the sixth embodiment of the type to be attachedto the periphery of the opening 98 of the loading part 78 of thesemiconductor-manufacturing equipment of the minienvironment system ofthe present invention. Like the filter means 6 d of the clean-airinjecting device 1 d of the fourth embodiment, the filter means 6 f isformed as a rectangular frame by cylindrically shaped filters 10disposed in a plurality rows (two rows in FIG. 19) and connected to eachother at their ends by L-joints 32, which have an enough depth, todefine rectangular double passages 9 for air and an inside space 12,which is slightly larger than the periphery of the opening 98. Further,each L-joints 32 has an air-feed pipe 15 extending laterally and havingan air-feed port 15 a for receiving air from the air-supply device 2.

The filter means 6 f configured as discussed above is disposed in therectangular cavity 18 of a filter case 7. The cavity 18 has a depthgreater than that of the cavity 18 of the filter case 7 of the firstembodiment and is configured the same as the cavity 18 of the filtercase 7 in FIGS. 14 and 15, so that the double rows of the cylindricallyshaped filters 10 are encased in it. Apertures 22 are formed in theouter side plates 16 of the case 7 so that each outwardly extendingair-feed tube 15 of the L-joints 32 passes through the correspondingaperture. Further, the guide cover 8 configured as in the firstembodiment is detachably secured to the filter case 7 at its opening 19,to form the clean-air injection device 1 f as shown in FIG. 20. In FIG.20 the number 23 denotes sealing applied to each junction of eachair-feed tube 15 and the corresponding aperture 22 of the filter case 7.

Differing from the clean-air injection device 1 e of the fifthembodiment, the clean-air injection device 1 f of the sixth embodimenthas the four air-feed ports 15 a to receive air from the air-supplydevice 2. Accordingly, the air supply tube 3, which is connected to theair-supply device 2 at one end, is branched to four sub-air-supply tubes3 a, 3 b, 3 c, and 3 d, which are in turn connected to the air-feedtubes 15. Using the clean-air injection device 1 f of the sixthembodiment can cause the air to be more uniformly injected from theinjection slit 25 and can give a greater flow rate of the air injectedfrom it than using the clean-air injection device 1 e of the fifthembodiment. The other functions of it are the same as the clean-airinjection device 1 a of the first embodiment, and thus the descriptionfor them is omitted.

FIG. 21 is a perspective view of filter means 6 g of a clean-airinjecting device 1 g of the seventh embodiment of the type to beattached to the periphery of the opening 98 of the loading part 78 ofthe semiconductor-manufacturing equipment of the minienvironment systemof the present invention. Like the first embodiment, the clean-airinjecting device 1 g, which is provided with the filter means 6 g, isconnected to the air-supply device 2 through an air-supply tube 3 asshown in FIG. 24. Further, the filter means 6 g differs from the filtermeans 6 d of the clean-air injection device 1 d of the fourth embodimentin that the filter means 6 g is formed as a rectangular frame bycylindrically shaped filters 10 disposed in a plurality of rows in thedirections of their width (two rows in FIG. 21), while the cylindricallyshaped filters 10 of the fourth embodiment are disposed in rows in thedirection of their depth.

The clean-air supply device 1 g of the seventh embodiment may be usedwhen the air to be injected is increased by enlarging the area of thefilters, or when the width and height of the filter case can be great,but its depth must be less. In this embodiment the cylindrically shapedfilters 10 are disposed in rows in the direction of their width (orheight) to increase the area of the filters to increase the air to beinjected.

More specifically, the filter means 6 g is formed as a rectangular frameby the cylindrically shaped filters 10 disposed in rows in the directionof their widths and jointed at their ends by L-joints 34, which haveenough widths, to define rectangular double passages 9 for air and aninside space 12, which is slightly larger than the periphery of theopening 98. The central parts of the upper or lower set of lateralfilters 10 (the upper set in FIG. 21) are cut away to create a spacingpart 13 between the cut ends 10 a and 10 b, and the cut ends 10 a, 10 bare connected by a I-joint 35, which has an enough width (height). TheI-joint 35 is formed with an air-feed tube 15, which extends upwardly,and which has an air-feed port 15 a for receiving air from theair-supply device 2.

The filter means 6 g configured as discussed above is disposed in therectangular cavity 18 of a filter case 7. The cavity 18 has a widthgreater than that of the cavity 18 of the filter case 7 of the firstembodiment as shown in FIGS. 22 and 23, so that the rows of thecylindrically shaped filters 10 are encased in it. An aperture 22 isformed in the outer side plate 16 of the case 7 so that the outwardlyextending air-feed tube 15 of the I-joint 35 passes through the aperture22. Further, the guide cover 8 configured as in the first embodiment isdetachably secured to the filter case 7 at its opening 19, to form theclean-air injection device 1 g as shown in FIG. 24. In FIG. 24 thenumber 23 denotes sealing applied to the junction of the air-feed tube15 and the aperture 22 of the filter case 7.

One function in the seventh embodiment that differs from that of thefirst embodiment is to increase the air to be injected by increasing thearea of the filters. Since the other functions of it are the same as thefirst embodiment, the description for them is omitted.

FIG. 25 is a perspective view of filter means 6 h of a clean-airinjecting device 1 h of the eighth embodiment of the type to be attachedto the periphery of the opening 98 of the loading part 78 of thesemiconductor-manufacturing equipment of the minienvironment system ofthe present invention. Like the filter means 6 g of the clean-airinjection device 1 g of the seventh embodiment, the filter means 6 h isformed as a rectangular frame by cylindrically shaped filters 10disposed in rows in the direction of their width (two rows in FIG. 25)and connected at their ends by L-joints 34, which have enough widths, toform double passages 9 for air and an inside space 12, which is slightlylarger than the periphery of the opening 98. The two of the L-joints 34,located at the left or right of the filter means (at the left in FIG.25), have air-feed tubes 15 extending laterally and having air-feedports 15 a for receiving air from the air-supply device 2.

The filter means 6 h configured as discussed above is disposed in therectangular cavity 18 of a filter case 7. The cavity 18 has a widthgreater than that of the cavity 18 of the filter case 7 of the firstembodiment as shown in FIGS. 22 and 23, so that the rows of thecylindrically shaped filters 10 are encased in it. Apertures 22 areformed in the outer side plate 16 of the case 7 so that the outwardlyextending air-feed tubes 15 of the L-joints 34 pass through theapertures 22. Further, the guide cover 8 configured as in the firstembodiment is detachably secured to the filter case 7 at its opening 19,to form the clean-air injection device 1 h as shown in FIG. 26. In FIG.26 the number 23 denotes sealing applied to the junctions of theair-feed tubes 15 and the apertures 22 of the filter case 7.

Differing from the clean-air injection device 1 g of the seventhembodiment, the clean-air injection device 1 h of the eighth embodimenthas the two air-feed ports 15 a for receiving air from the air-supplydevice 2. Accordingly, as in FIG. 26 the air-supply tube 3, which isconnected to the air-supply device 2 at one end, is branched to twosub-air-supply tubes 3 a, 3 b through a branching box 31, and the tubes3 a, 3 b are in turn connected to the air-feed tubes 15.

Using the clean-air injection device 1 h of the eighth embodiment cancause the air to be more uniformly injected from the injection slit 25and can give a greater flow rate of the air injected from it than usingthe clean-air injection device 1 g of the seventh embodiment. The otherfunctions of it are the same as the clean-air injection device 1 a ofthe first embodiment, and thus the description for them is omitted.

FIG. 27 is a perspective view of filter means 6 i of a clean-airinjecting device 1 i of the ninth embodiment of the type to be attachedto the periphery of the opening 98 of the loading part 78 of thesemiconductor-manufacturing equipment of the minienvironment system ofthe present invention. Like the filter means 6 g of the clean-airinjection device 1 g of the seventh embodiment, the filter means 6 i isformed as a rectangular frame by cylindrically shaped filters 10disposed in rows in the direction of their width (two rows in FIG. 27)and connected at their ends by L-joints 34, which have enough widths, toform double passages 9 for air and an inside space 12, which is slightlylarger than the periphery of the opening 98. Each L-joint 34 has anair-feed tube 15 extending laterally and having an air-feed port 15 afor receiving air from the air-supply device 2.

The filter means 6 i configured as discussed above is disposed in therectangular cavity 18 of a filter case 7. The cavity 18 has a widthgreater than that of the cavity 18 of the filter case 7 of the firstembodiment as shown in FIGS. 22 and 23, so that the rows of thecylindrically shaped filters 10 are encased in it. Apertures 22 areformed in the outer side plates 16 of the case 7 so that the outwardlyextending air-feed tubes 15 of the L-joints 34 pass through theapertures 22. Further, the guide cover 8 configured as in the firstembodiment is detachably secured to the filter case 7 at its opening 19,to form the clean-air injection device 1 i as shown in FIG. 28. In FIG.28 the number 23 denotes sealing applied to the junctions of theair-feed tubes 15 and the apertures 22 of the filter case 7.

Differing from the clean-air injection device 1 h of the eighthembodiment, the clean-air injection device 1 i of the ninth embodimenthas the four air-feed ports 15 a for receiving air from the air-supplydevice 2. Accordingly, as in FIG. 28 the air-supply tube 3, which isconnected to the air-supply device 2 at one end, is branched at itsintermediate part to four sub-air-supply tubes 3 a, 3 b, 3 c, 3 dthrough a branching box 31, and the tubes 3 a, 3 b, 3 c, 3 d are in turnconnected to the air-feed tubes 15.

Using the clean-air injection device 1 i of the ninth embodiment cancause the air to be more uniformly injected from the injection slit 25and can give a greater flow rate of the air injected from it than usingthe clean-air injection device 1 h of the eighth embodiment. The otherfunctions of it are the same as the clean-air injection device 1 a ofthe first embodiment, and thus the description for them is omitted.

According to the semiconductor-fabrication equipment of theminienvironment system of the present invention provided with theclean-air injection device discussed above of the type to be attached tothe periphery of the opening of the loading part, when the lid 75 of thehermetic container 71 is opened into the semiconductor-fabricationequipment and a wafer 73 is taken out by the arm 93, or when a processedwafer is put in the hermetic container 71 by the arm 93, the clean airinjected form the injection slit 25 of the clean-air injection device 1connected to the air-supply device 2 through the air-supply tube 3 isinjected from the guide slit 29 as shown by straight lines (in FIGS. 1and 2) to form an air curtain at the gap 96 between the opening 98 andthe gateway 74, to prevent the dust-entrained ambient air from passingthrough the gap into the hermetic container 71 as shown in the curbedarrows (in FIGS. 1 and 2). Thus the dust is prevented from adhering tothe wafers 73 of the hermetic containers 71.

FIG. 29 is a schematic sectional view of the main part of thesemiconductor-fabrication equipment of the minienvironment systemprovided with a clean-air injection device embedded in the periphery ofthe opening 98 of the loading part 78, wherein a clean-air injectiondevice 111 a of the first embodiment is used. FIG. 30 is a schematicfront view taken from the loading part side. The clean-air injectiondevice 111 a of the first embodiment is embedded in the periphery of theopening 98 of the loading part 78, formed in the front panel 77 of thesemiconductor-fabrication device 76.

That is, like the clean-air injection device 1 attached to the peripheryof the opening 98 of the loading part 78 as shown in FIGS. 1 and 2, theclean-air injection device 111 a of the first embodiment is connectedthrough the air-supply tube 113 to the air-supply device 112 mounted onthe inner surface of the front panel 77 for sucking air in the highcleanliness space 81. Further, in the clean-air injection device 111 a arectangular, concave notch 114 is formed at the periphery of the opening98 of the front panel 77. The concave notch 114 is opened toward theloading part. Filter means 119 is formed as in FIG. 9, where thecylindrically shaped filters 115 are connected at their ends by theL-joints 116, to define a rectangular air passage 117, and two L-joints116 located at one side are formed with air-feed tube 118 extendinglaterally for receiving air from the air-supply device 112. The filtermeans 119 is placed in the notch 114.

Further, in the clean-air injection device 111 a each air-feed tube 118passes through a rear plate 120 of the notch 114 into the highcleanliness space 81 and is connected there to the air-supply tube 113.A cover 123, which is formed as a rectangular frame, is mounted on thefront of the notch 114. The cover 123 has guide plates 122 angled toguide air and to define a slit 121 between the angled protrudingportions along the rectangular frame. Thus an air space 124 is definedaround the filter means 119. The slit 121 is located at the center ofthe rectangular frame for injecting clean air that has passed the filtermeans 119. The size (width) of the slit may not be limited to a specialsize. It is preferably 1.5 mm.

In FIGS. 29 and 30 the number and letter 122 a denotes spot welding,which are applied between the guide plates 122 at the spacing of about 5cm to joint them so that they cannot be separated into two cover members125 a, 125 b.

According to the semiconductor-fabrication equipment of theminienvironment system of the present invention that uses the clean-airinjection device 111 a configured as discussed above, when the air inthe high cleanliness space 81 is pumped to the filer means 119 from theair-supply device 2 through the air-supply tube 113, the air is pumpedinto the air passage 117 of the cylindrically shaped filters 115 of thefilter means 119 and is filtered by the filters 115 to become more cleanthan the air in the in the high cleanliness space 81, and the more cleanair injected into the air space 124 is then injected from the injectionslit 121. The other functions are the same as those in thesemiconductor-fabrication equipment of the present invention that usesthe clean-air injection device 1. Thus the description for them isomitted.

FIG. 31 is a schematic sectional view of the main part of thesemiconductor-fabrication equipment of the minienvironment systemprovided with a clean-air injection device embedded in the periphery ofthe opening 98 of the loading part 78, wherein a clean-air injectiondevice 111 b of the second embodiment is used. FIG. 32 is a schematicfront view taken from the loading part side. The clean-air injectiondevice 111 b of the second embodiment is embedded in the periphery ofthe opening 98 of the loading part 78, like the clean-air injectiondevice 111 a of the first embodiment.

Further, the clean-air injection device 111 b of the second embodimentdiffers from the clean-air injection device 111 a of the firstembodiment in the shapes of a notch 114 and a cover 123, and the otherstructures of it are the same as those of the clean-air injection device111 a of the first embodiment.

That is, like the clean-air injection device 111 a of the firstinvention, the clean-air injection device 111 b of the second embodimentis connected through the air-supply tube 113 to the air-supply device112 mounted on the inner surface of the front panel 77 for sucking airin the high cleanliness space 81. Further, in the clean-air injectiondevice 111 a a rectangular (annular), hook-shaped notch 114 is formed atthe periphery of the opening 98 of the front panel 77. The notch 114 isopened toward the loading part. Filter means 119 is formed as in FIG. 9,where the cylindrically shaped filters 115 are connected at their endsby the L-joints 116, to define a rectangular air passage 117, and twoL-joints 116 located at one side are formed with air-feed tube 118extending laterally for receiving air from the air-supply device 112.The filter means 119 is placed in the notch 114.

Further, in the clean-air injection device 111 b each air-feed tube 118passes through a rear plate 120 of the notch 114 into the highcleanliness space 81 and is connected there to the air-supply tube 113.A cover 123, which has a hook-shaped cross section, and which is formedas a rectangular frame, is mounted on the front of the notch 114. Thecover 123 has guide plates 122 angled to guide air and to define a slit121 between the angled protruding portions along the rectangular frame.Thus an air space 124 is defined around the filter means 119. The slit121 is located at the center of the rectangular frame for injectingclean air that has passed the filter means 119. The size (width) of theslit may not be limited to a special size. It is preferably 1.5 mm.

In FIGS. 32 and 33 the number and letter 122 a denotes spot welding,which are applied between the guide plates 122 at the spacing of about 5cm to joint them so that they cannot be separated into two cover members125 a, 125 b.

The main function of the semiconductor-fabrication equipment of theminienvironment system of the present invention that uses the clean-airinjection device 111 b configured as discussed above is the same as thatof the system that uses the clean-air injection device 111 a of thefirst embodiment. The other functions are the same as those in thesemiconductor-fabrication equipment of the present invention that usesthe clean-air injection device 1. Thus the description for them isomitted.

FIG. 33 is a schematic sectional view of the main part of thesemiconductor-fabrication equipment of the minienvironment systemprovided with a clean-air injection device embedded in the periphery ofthe opening 98 of the loading part 78, wherein a clean-air injectiondevice 111 c of the third embodiment is used. FIG. 34 is a schematicfront view taken from the loading part side. The clean-air injectiondevice 111 c of the third embodiment is embedded in the periphery of theopening 98 of the loading part 78, like the clean-air injection device111 a of the first embodiment.

Further, the clean-air injection device 111 c of the third embodimentdiffers from the clean-air injection device 111 b of the secondembodiment in that it does not use an air-supply tube 113, and the otherstructures of it are the same as those of the clean-air injection device111 b of the second embodiment.

That is, the clean-air injection device 111 c of the third embodiment isconnected to the air-supply device 112 mounted on the inner surface ofthe front panel 77 for sucking air in the high cleanliness space 81through an air-supply passage 131 disposed in the front panel 77. Asshown in FIGS. 33 and 35, the air-supply passage 131 is formed as anair-supply groove 132, which is formed in the front panel 77 at the highcleanliness space 81 side, and which is covered by a cover plate 133 atthe high cleanliness space 81 side. The air-supply passage 131 is influid communication with the air-supply device 112 and extends upwards.

Further, in the clean-air injection device 111 c a rectangular(annular), hook-shaped notch 114 is formed at the periphery of theopening 98 of the front panel 77. The notch 114 is opened toward theloading part. Filter means 119 is formed as in FIG. 9, where thecylindrically shaped filters 115 are connected at their ends by theL-joints 116, to define a rectangular air passage 117, and two L-joints116 located at one side are formed with air-feed tube 118 extendinglaterally for receiving air from the air-supply device 112. The filtermeans 119 is placed in the notch 114.

Further, in the clean-air injection device 111 c each air-feed tube 118passes through a rear plate 120 of the notch 114 and is connected to theair-supply passage 131. The other structures and the functions of thesemiconductor-fabrication device of the invention that uses theclean-air injection device 111 c are similar to thesemiconductor-fabrication device of the invention that uses theclean-air injection device 111 a. Thus a further description for them isomitted.

According to the semiconductor-fabrication equipment of theminienvironment system of the present invention that uses the clean-airinjection device configured as discussed above, of the type to beembedded in the periphery of the opening of the loading part, when thelid 75 of the hermetic container 71 is opened into thesemiconductor-fabrication equipment and a wafer 73 is taken out by thearm 93, or when a processed wafer is put in the hermetic container 71 bythe arm 93, the clean air is injected form the injection slit 121 of theclean-air injection device 111 connected to the air-supply device 112through the air-supply tube 113 or the air-supply passage 131 to form anair curtain at the gap 96 between the opening 98 and the gateway 74, toprevent the dust-entrained ambient air from passing through the gap intothe hermetic container 71. Thus the dust is prevented from adhering tothe wafers 73 in the hermetic containers 71. Since the clean-airinjection device 111 has been previously embedded in the periphery ofthe opening 98 of the loading part 78, the semiconductor-fabricationdevice is not crenellated (i.e., flat) and has a good appearance.Further, like the clean-air injection device 1 of the type to beattached to the periphery of the opening 98, the cover 123 can be easilyremoved for changing the filter means 119 with a new one.

Since the present invention is configured as discussed above, when awafer 73 is taken out of the hermetic container, or when a processedwafer is put in the hermetic container, the clean air is injected formthe injection slit of the clean-air injection device connected to theair-supply device through the air-supply tube or the air-supply passageto form an air curtain at the gap between the opening of the loadingpart attached to the semiconductor-fabrication equipment and the gatewayof the hermetic container, to prevent the dust-entrained ambient airfrom passing through the gap into the hermetic container. Thus the dustis prevented from adhering to the wafers in the hermetic containers 71.

1. An air curtain forming apparatus for attachment to a semiconductorfabrication equipment, the semiconductor fabrication equipment having anopening that permits a wafer to be transferred to or from a hermeticcontainer, the air curtain forming apparatus comprising: cylindricallyshaped filters connected to each other, one filter having an air supplytube; a filter case forming a rectangular frame and encasing thecylindrically shaped filters, the filter case having a front opening andan aperture wherein the air supply tube passes through the aperture; anda guide cover having an injection slit and a guide slit, the guide coverremovably mounted on the filter case at its front opening, such that airsupplied to the air supply tube passes through the injection slit and isejected from the apparatus through the guide slit forming an air curtainat a gap between the opening and a gateway of the hermetic container toprevent ambient air from entering the hermetic container when thehermetic container is opened.
 2. An air-curtain forming apparatus to beattached to a semiconductor-fabrication equipment of a minienvironmentsystem, in which system a wafer is conveyed by a wafer hermeticcontainer to the semiconductor-fabrication equipment equipped with awafer carrying-in opening, comprising: an annular case to be attached toa periphery of the wafer carrying-in opening, the case having a slit forinjecting air forwardly; an annular air filter tube disposed in thecase, the air filter tube having a circular cross section; an air-supplymeans for supplying an airflow into the annular air filter tube so thatthe airflow passes through the air filter tube and is injected from theslit; and an air-supply tube for connecting the air-supply means and theair filter tube in fluid communication, thereby forming an air curtainof clean air that has passed the annular air filter tube, between aperiphery of an opened opening of the hermetic container and a peripheryof the wafer carrying-in opening to prevent ambient air from enteringthe opened opening of the hermetic container when the hermeticcontainer, which is located in front of the wafer carrying-in opening ofthe semiconductor fabrication device, is opened.
 3. The air-curtainforming apparatus of claim 2, including a guide plate for directing theclean air that has passed the air filter tube.
 4. The air-curtainforming apparatus of claim 2, wherein the air-supply tube is attached toa front panel of the semiconductor-fabrication equipment, and whereinthe annular case is disposed in a notch formed in the front panel at theperiphery of the wafer carrying-in opening formed in the front panel. 5.An air-curtain forming apparatus to be attached to asemiconductor-fabrication equipment of a minienvironment system, inwhich system a wafer is conveyed by a wafer hermetic container to thesemiconductor-fabrication equipment equipped with a wafer carrying-inopening, comprising: an annular case to be attached to a periphery ofthe wafer carrying-in opening, the case having a slit for injecting airforwardly; an annular air filter tube disposed in the case, the airfilter tube having a circular cross section; an air-supply means forsupplying an airflow into the annular air filter tube so that theairflow passes through the air filter tube and is injected from theslit; and an air-supply tube for connecting the air-supply means and theair filter tube in fluid communication, thereby forming an air curtainof clean air that has passed the annular air filter tube, between aperiphery of the wafer carrying-in opening and a periphery of an openedopening of one hermetic container located in front of the wafercarrying-in opening to prevent ambient air from entering the opening ofsaid hermetic container when the opening of said hermetic container, isopened.
 6. The air-curtain forming apparatus of claim 5, including aguide plate for directing the clean air that has passed the air filtertube.
 7. The air-curtain forming apparatus of claim 5, wherein theair-supply tube is attached to a front panel of thesemiconductor-fabrication equipment, and wherein the annular case isdisposed in a notch formed in the front panel at the periphery of thewafer carrying-in opening formed in the front panel.